1. Field of the Invention
The present invention relates to a safety mobile ladder stand and more particularly, to a large ladder stand which can be used in small spaces where mobility of a larger ladder stand is restricted.
2. Description of the Prior Art
Mobile or safety ladder stands are generally known in the industry and are used by workers and persons who need to reach products or materials stored on shelves in stores and warehouses. Such safety ladder stands also generally incorporate a rolling/locking mechanism so that the ladder stand can be moved easily to different locations in the warehouse or building when such a mechanism is actuated. With such a construction, the rolling/locking mechanism is deactivated when the mobile ladder stand is to be used such as when a person climbs on it to reach overhead shelves or spaces. The deactivation of the rolling/locking mechanism stabilizes the ladder stand in a fixed position thereby allowing for a safer and steadier use of the stand.
Some large mobile ladder stands with rolling/locking mechanisms are difficult or awkward to maneuver in small spaces such as in the aisleways of stores or warehouses. This is due to the fact that the length of the base must be increased to accommodate a taller ladder stand. Since such ladder stands are generally supported by wheel sets at all four corners of the base, a longer base makes turning of the stand difficult.
The problem stated previously was addressed in part in U.S. Pat. No. 5,941,341 entitled "Mobile Ladder Stand" which issued on Aug. 24, 1999. This patent discloses a safety ladder stand having a generally rectangular base having a front and rear and a center beam, with a plurality of stair treads extending upwards from the front of the base and means for supporting the stair treads secured to the base. Front wheels are mounted at the front of the base and beneath the top of the stair treads, with center wheels mounted on the center beam of the base and rear wheels mounted at the rear of the base. A set of feet are mounted at the front of the base. The ladder stand has an activated position and a deactivated position. In the activated position, the front and center wheel sets are in contact with the ground to enable the ladder stand to roll and the rear wheels and front support feet are out of contact with the ground. In the deactivated position of the ladder stand, the front and center wheel sets are not in contact with the ground and the rear wheels and the front wheels are in contact with the ground to prevent the ladder stand from being rolled. It includes means for moving the ladder stand from the deactivated position to the activated position.
The assignee of the present invention has manufactured for many years relatively small ladder stands with five to nine steps which are provided with a base having wheel supports at the front and rear of the stand. Each wheel support is provided with a safe-lock mechanism and a pair of swivable casters or wheels rotatable throughout 360.degree.. The use of the safe-lock mechanism and swivable caster wheels at the rear end of the base allows the ladder stand to be more readily maneuverable in confined spaces.
The assignee of the present invention has also manufactured for many years relatively large ladder stands with six to nineteen steps, as an example, having a base with a safety lock mechanism and a pair of swivable caster wheels at the front and a pair of rigid caster wheels at the rear of the base. It is difficult with such a construction to maneuver the large ladder stands in confined spaces.
While a great variety of mobile ladder stands have been heretofore been proposed, nevertheless there remains a need for improved relatively large mobile ladder stands which are simple in construction, are relatively inexpensive to manufacturer and are convenient to use.